using UnityEngine;
using System.Collections.Generic;
using Assets.WasapiAudio.Scripts.Unity;

[RequireComponent(typeof(Material))]
public class ThemeShaderBinder : MonoBehaviour
{
    public Material material;
    public Preferences preferences;

    private Texture2D _texture;
    private Color[] _colorCache;
    private int textureSize = 128;

    private void Start() {
        if (preferences == null) {
            Debug.Log("Theme Shader Binder needs Preferences.");
            gameObject.SetActive(false);
        }
    }

    private void Update() {
        UpdateTexture();
        UpdateBinding();
    }

    private void InitialiseTexture() {
        Debug.Log("Reinitialising spectrum texture...");
        _texture = new Texture2D(textureSize, 1);
        _colorCache = new Color[textureSize];
        _texture.name = $"ThemeTexture{textureSize}";
    }

    private void UpdateTexture() {
        // init
        if (_texture == null) InitialiseTexture();

        Gradient theme = preferences.Theme();
        for (int i = 0; i < textureSize; i++) {
            _colorCache[i] = theme.Evaluate((float)i / (float)textureSize);
        }

        _texture.SetPixels(_colorCache);
        _texture.Apply();
    }

    public void UpdateBinding() {
        UpdateTexture();
        material.SetFloat("_ThemeSize", textureSize);
        material.SetTexture("_ThemeTexture", _texture);
    }
}